/*-------------------------------------------------------------------------
 * drawElements Thread Library
 * ---------------------------
 *
 * Copyright 2014 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 *//*!
 * \file
 * \brief Win32 implementation of thread management.
 *//*--------------------------------------------------------------------*/

#include "deThread.h"

#if (DE_OS == DE_OS_WIN32 || DE_OS == DE_OS_WINCE)

#include "deMemory.h"
#include "deInt32.h"

#define VC_EXTRALEAN
#define WIN32_LEAN_AND_MEAN
#include <windows.h>

/* Thread handle equals deThread in this implementation. */
DE_STATIC_ASSERT(sizeof(deThread) >= sizeof(HANDLE));

typedef struct ThreadEntry_s
{
    deThreadFunc func;
    void *arg;
} ThreadEntry;

static int mapPriority(deThreadPriority priority)
{
    switch (priority)
    {
    case DE_THREADPRIORITY_LOWEST:
        return THREAD_PRIORITY_IDLE;
    case DE_THREADPRIORITY_LOW:
        return THREAD_PRIORITY_LOWEST;
    case DE_THREADPRIORITY_NORMAL:
        return THREAD_PRIORITY_NORMAL;
    case DE_THREADPRIORITY_HIGH:
        return THREAD_PRIORITY_ABOVE_NORMAL;
    case DE_THREADPRIORITY_HIGHEST:
        return THREAD_PRIORITY_HIGHEST;
    default:
        DE_ASSERT(false);
    }
    return 0;
}

static DWORD __stdcall startThread(LPVOID entryPtr)
{
    ThreadEntry *entry = (ThreadEntry *)entryPtr;
    deThreadFunc func  = entry->func;
    void *arg          = entry->arg;

    deFree(entry);

    func(arg);

    return 0;
}

deThread deThread_create(deThreadFunc func, void *arg, const deThreadAttributes *attributes)
{
    ThreadEntry *entry = (ThreadEntry *)deMalloc(sizeof(ThreadEntry));
    HANDLE thread      = 0;

    if (!entry)
        return 0;

    entry->func = func;
    entry->arg  = arg;

    thread = CreateThread(DE_NULL, 0, startThread, entry, 0, DE_NULL);
    if (!thread)
    {
        deFree(entry);
        return 0;
    }

    if (attributes)
        SetThreadPriority(thread, mapPriority(attributes->priority));

    return (deThread)thread;
}

bool deThread_join(deThread thread)
{
    HANDLE handle = (HANDLE)thread;
    WaitForSingleObject(handle, INFINITE);

    return true;
}

void deThread_destroy(deThread thread)
{
    HANDLE handle = (HANDLE)thread;
    CloseHandle(handle);
}

void deSleep(uint32_t milliseconds)
{
    Sleep((DWORD)milliseconds);
}

void deYield(void)
{
    SwitchToThread();
}

static SYSTEM_LOGICAL_PROCESSOR_INFORMATION *getWin32ProcessorInfo(uint32_t *numBytes)
{
    uint32_t curSize                           = (uint32_t)sizeof(PSYSTEM_LOGICAL_PROCESSOR_INFORMATION) * 8;
    SYSTEM_LOGICAL_PROCESSOR_INFORMATION *info = (SYSTEM_LOGICAL_PROCESSOR_INFORMATION *)deMalloc(curSize);

    for (;;)
    {
        DWORD inOutLen = curSize;
        DWORD err;

        if (GetLogicalProcessorInformation(info, &inOutLen))
        {
            *numBytes = inOutLen;
            return info;
        }
        else
        {
            err = GetLastError();

            if (err == ERROR_INSUFFICIENT_BUFFER)
            {
                curSize <<= 1;
                info = deRealloc(info, curSize);
            }
            else
            {
                deFree(info);
                return DE_NULL;
            }
        }
    }
}

typedef struct ProcessorInfo_s
{
    uint32_t numPhysicalCores;
    uint32_t numLogicalCores;
} ProcessorInfo;

void parseWin32ProcessorInfo(ProcessorInfo *dst, const SYSTEM_LOGICAL_PROCESSOR_INFORMATION *src, uint32_t numBytes)
{
    const SYSTEM_LOGICAL_PROCESSOR_INFORMATION *cur = src;

    deMemset(dst, 0, sizeof(ProcessorInfo));

    while (((const uint8_t *)cur - (const uint8_t *)src) + sizeof(SYSTEM_LOGICAL_PROCESSOR_INFORMATION) <= numBytes)
    {
        if (cur->Relationship == RelationProcessorCore)
        {
            dst->numPhysicalCores += 1;
#if (DE_PTR_SIZE == 8)
            dst->numLogicalCores += dePop64(cur->ProcessorMask);
#else
            dst->numLogicalCores += dePop32(cur->ProcessorMask);
#endif
        }

        cur++;
    }
}

bool getProcessorInfo(ProcessorInfo *info)
{
    uint32_t numBytes                             = 0;
    SYSTEM_LOGICAL_PROCESSOR_INFORMATION *rawInfo = getWin32ProcessorInfo(&numBytes);

    if (!numBytes)
        return false;

    parseWin32ProcessorInfo(info, rawInfo, numBytes);
    deFree(rawInfo);

    return true;
}

uint32_t deGetNumTotalPhysicalCores(void)
{
    ProcessorInfo info;

    if (!getProcessorInfo(&info))
        return 1u;

    return info.numPhysicalCores;
}

uint32_t deGetNumTotalLogicalCores(void)
{
    ProcessorInfo info;

    if (!getProcessorInfo(&info))
        return 1u;

    return info.numLogicalCores;
}

uint32_t deGetNumAvailableLogicalCores(void)
{
    return deGetNumTotalLogicalCores();
}

#endif /* DE_OS */